occur vs appear

occur and appear both are verbs.

Word	Noun	Adjective	Verb	Adverb
occur	No	No	Yes	No
appear	No	No	Yes	No

As verbs, appear is a hypernym of occur; that is, appear is a word with a broader meaning than occur:

Other hypernyms of occur include come along.

occur (verb)	appear (verb)
come to pass	come into sight or view
come to one's mind; suggest itself	be issued or published
to be found to exist	come into being or existence, or appear on the scene
	appear as a character on stage or appear in a play, etc.
	give a certain impression of being something or having a certain aspect
	(of a proposition) seem to be true, probable, or apparent
	present oneself formally, as before a (judicial) authority